Technical Field
The present disclosure generally relates to communication among integrated circuit chips and, in particular, to determining which one of a pair of chips will assume control of a shared communication link following detection of a signal event.
Description of the Related Art
In some electronic circuits, it is beneficial to coordinate electrical signals transmitted among components such as integrated circuit chips. For example, it may be desirable for a microelectronic controller that communicates signals to external chips to present the same pattern of control logic or control waveforms to multiple chips to ensure that signal events are communicated to all of the chips, not just one chip. More specifically, in the case of devices such as smart phones that include touch panels, more than one controller may be used to drive an entire touch screen. In one example, a first controller may control the bottom of the screen while a second controller controls the top of the screen. Thus, it may be beneficial for the same waveform pattern to be delivered to both halves of the touch screen panel. In another example, when one controller detects a signal event such as signal noise, the signal event is communicated to the other controller so that the two chips remain synchronized. In such a situation, the chip that detects the signal event first is typically designated as the master and the other chip is designated as the slave.
A straightforward way to maintain such synchronization is to configure the two chips with a pair of input/output (I/O) pads on each chip, and two separate communication paths, as shown in FIG. 1. In this way, whichever chip detects the signal event first can notify the other chip of the status via a dedicated communication path. However, maintaining two separate dedicated, unidirectional communication paths and four associated I/O ports consumes valuable chip real estate and operational resources.